DK165519B - CLOSE VALVE WITH LEAKAGE SPACES - Google Patents

Description

in

DK 165519B

The invention relates to a shut-off valve as described in the preamble of claim 1. Such a shut-off valve is known from European Patent Specification No. 39,319. The closure valve shown and described in this patent has a valve body with an upper and lower part, which upper part has an axial seal, and which lower part has a radial sealing ring where its radially outer perimeter can cooperate with the cylindrical surface at the valve seat. The upper part of the valve body has a recess with a cylindrical surface 10 having the same diameter as the cylindrical surface at the valve seat. To open this known valve, the lower portion of the valve body is moved upward, its sealing ring cooperating with the recess in the upper portion of the valve body. Thus, the two parts are moved together to actually open the passage.

The axial seal at the upper valve body has a larger diameter than the sealing passages, so that this axial valve seat defines an area 20-25% greater than that of the passengers. This means that for opening the valve 20 a force is required, which depends to a considerable extent on the pressure in the medium in the closing valve. In the initial phase of the opening of the valve, in which the axial valve seat is still engaged, and in the final phase of the closure of the valve, when the radial seal is not yet engaged, 25 reaction forces on the valve body can occur with the occurrence of compressional shock. the cables, which otherwise cause closing or opening of the valve itself. Further, separate inlet and outlet positions 30 are provided for flushing the leak detection or flushing chamber in the valve body for supplying and removing flushing fluid. Separate pipes and valve devices are needed to flush this shut-off valve.

The invention has for its object to provide a closure valve of the kind mentioned earlier, which can be more easily operated and flushed.

2

DK 165519B

This object is achieved in a closure valve according to the invention, which is characterized by the characterizing part of claim 1. When opening and closing the valve, the resulting forces on the valve body are fully balanced as a result of the pressure in the pipes, so that the movable part only has to overcome the friction on the valve body at the area of the seals as well as the spring force. Furthermore, no reaction forces occur due to pressure shocks in the pipes.

An important aspect of the invention is that in order to obtain a good seal, it is not necessary to press the valve body with a biasing force against the valve seat. The seal of the sealing ring in a cylindrical valve seat surface provides a perfectly secure seal. Therefore, the movable part of the closing valve 15 according to the invention may also be light, since such biasing force is not to be overcome. Furthermore, rinsing of leak detection chambers can be accomplished in a simple manner at the same time as any of the chambers is flushed when the movable portion establishes the first or second rinsing position.

The invention will now be explained in more detail with reference to the drawing, in which: FIG. 1-4 show a longitudinal section through a shut-valve embodiment of the invention with leak detection in four different working positions; 5 is a longitudinal section through another embodiment of a shut-off valve according to the invention with leak detection; and FIG. 6 is the one shown in FIG. 5, the closing valve shown separately.

In FIG. 1-4 shows a shut-off valve 40 in the form of a single-30 shutter. The shut-off valve has a housing 41 with two chambers 42 and 43 adjacent to each other in the axial direction. The chambers 42 and 43 communicate with fluid channels via ports 44 and 45, respectively. In addition, the chambers 42 and 43 have a valve seat 46. In the housing 41, a valve body 47 can be displaced axially 35, which body has an upper part 48 and a bottom. 3

DK 165519B

part 49, as will be described below.

At the valve seat 46, the upper portion 48 has a sealing ring 50, while the lower valve body portion 49 has a sealing ring 51 also at the valve seat 46. The proximal faces of the upper valve 5 conduit portion 48 and the lower valve portion 49 have shutter portions 53 formed by a sealing ring. the lower portion 49 cooperating with a suitable radial surface of the upper portion 48. The upper portion 48 and the lower portion 49 may be moved in contact with each other so that the closure portion 53 seals the upper portion and the lower portion to form a closed device.

FIG. 1 shows the closing valve 40 in the resting position. In this resting position, the lower body portion 49 and the upper body portion 48 are moved away from each other in the axial direction to a relatively open position. The cylindrical valve seat 46 has such an axial length that the two sealing rings 50 and 51 in this relatively open position are sealingly engaged with the seat 46. The lower body portion 49 has an axial bore 54 which communicates with the space between the sealing rings 50 and 20 51 via a transverse bore 55. If one of the sealing rings 50 or 51 does not close completely, the medium, especially liquid, will run from the chambers 42 or 43 to the space 52. From this space 52, the medium flows through the transverse bore 55 into the the leak detection channel 54. The medium that leaks is delivered at the lower end of the leak detection channel 54 so that it becomes visible and signaled that there is a leak. In this way, the medium flowing through the channels communicating with the ports 44 is prevented from being mixed with the medium flowing through the channels communicating with the ports 45 or vice versa. In a transport plant in the food and beverage industry, one of the channels can carry product liquid and the other channel can carry a cleaning fluid. An obvious example is the dairy industry where the closing valve 40 is used, for example in a milk processing device. In such a device, the channels must be repeatedly cleaned to avoid growth of lactic acid bacteria in milk residues.

4

DK 165519B

In accordance with the invention, the guard core 47 in the closing valve 40 is also controlled at the top via a passage 56 and at the bottom via a passage 57. The diameters of the passages 56 and 57 and the diameter of the valve seat 46 are essentially identical. In this way, as described above, equalization of forces is ensured.

The valve body 47 is held in the position shown in FIG. 1 by the return spring 59. The lower end of the return spring 59 abuts an upper side of the spring chamber 58, which communicates with the closing valve housing 41. The upper end of the return spring abuts an end of a spring bush 60, the lower stop edge 61 of which lies abutting a lower edge of the lower valve body part 49. By applying the return spring 15 59 in this way partially in the valve body 47, closing the axial length of the valve is reduced.

The movable portion of the closing valve 40 also has a cylinder 62 located on the upper side of the housing 41 which may be a compressed air cylinder. The cylinder 62 has a cover 63 on the upper side. The cylinder 62 is double-acting and its upper part has an auxiliary piston 64, the function of which will be described below. The lower valve body portion 49 has a rod 65 extending upwardly through an axial bore in the upper valve body portion 48. This rod has a shoulder 25 which contacts the lower end of the auxiliary piston 64. In the embodiment shown in FIG. 1, the lower valve body member 49 is forced into its upper end position via the return spring 59. This upper end position is thus determined by the contact between the shoulder 30 66 of the rod 65 and the auxiliary piston 64, which in turn contacts the cylinder 63 cover 63.

The relatively open position of the upper valve body portion 48 relative to the lower valve body portion 49 is determined by resilient abutment means 69. In a preferred embodiment,

DK 165519 B

In accordance with the embodiment of the invention, these members have a radially extending collar 71 disposed on the upper valve body portion 48, a collar 70 formed by a spring ring covering substantially the same radial distance opposite the collar 71, and disposed on the rod 65 of the lower body portion 49, as well as a pressure ring 72 which engages on the upper side with the axial faces of the collars 70 and 71, and a pressure ring 73 which engages on the underside with the lower axial surfaces of the collars 70 and 71. The pressure ring 72 is spring-driven downwardly by a pressure spring 74 abutting the auxiliary piston 64. The lower pressure ring 73 is spring-shaped upwards by a pressure spring 75 supported by the rod 65 via a ring 76 and a spring ring 77. resilient abutment means 69, the upper swivel body portion 48 is held resiliently in the relatively open position relative to the lower body portion 49. A movement upwardly of the portion 48 relative to the portion 49 is counteracted by the spring 74 while a downward movement is counteracted by the spring 75.

The operation of the closing valve 40 will then be described in detail with reference to FIG. 2-4. For displacing the valve body 47 from the one shown in FIG. 1 to the rest position shown in FIG. 2, a pressure medium such as compressed air is supplied via a port 80 to the cylinder 62. The pressure exerted by the compressed air forces the upper valve body portion 48 downwards. The valve body portion 48 has at its upper end a sealing ring 67 which cooperates with the inner wall of the cylinder 62. In accordance with the invention, the force exerted by the spring 75 is less than the force exerted by the return spring 59. Accordingly, when the upper valve body portion 48 is forced downwardly by the compressed air, first the upper valve body portion 48 is lowered relative to the lower valve body portion. 49 until the underside of the upper valve body portion is in contact with the shutter portion 53. At this moment, the lower valve body portion 35 49, for its part, is still in the position shown in FIG. 1, i.e.

the sealing ring 51 is in contact with the valve seat 46. Upon further supply of compressed air through the port 80,

DK 165519 B

6 the upper valve body portion 48 further downwardly so that the lower valve body portion 49 is guided. This movement continues until the rim of the upper valve body portion with the seal contacts a rim 5 located below it in cylinder 62. This is the one shown in FIG. 2.

In this state, the passage 68 is free so that a medium can flow from the chamber 42 to the chamber 43 or vice versa.

When the closing valve 40 is to be returned to its closed position, the pressure in the cylinder 62 is allowed to escape, 10 so that the return spring 59 moves the entire valve body upwards. When the rim 66 of the rod 65 comes into contact with the underside of the auxiliary piston 64, the movement of the lower valve body portion 49 stops, and the upper valve body portion 48 moves negligibly further upwardly under the influence of the spring 75.

When, as in the example above, the milk has passed through the closing valve, some milk is left, after the device is closed, in the space between the two sealing rings 50 and 51. To avoid unwanted development of lactic acid bacteria in this milk residue, the space 53 and the leak detection channel 54 communicating with compartment 53 is flushed in the closure valve 40 of the invention while flushing the channels communicating with ports 44 or 45.

FIG. 3 shows the situation where the leak detection compartments 53 to 55 are flushed while the chamber 42 is flushed, and FIG. 4 shows the situation where the leak detection rooms are flushed while the chamber 43 is flushed.

The FIG. 3 arises from the situation shown in FIG. 130, when a pressure medium is applied, for example, compressed air to the port 8 of the cylinder 62. The upper valve body portion 48 is forced by this compressed air upwards in the cylinder 62 against the force of the spring 74 until the portion 48 contacts the auxiliary piston 64 via the pressure ring 72. 7

DK 165519B

Moving upward, the seal ring 50 is released from the valve seat 46 to establish a connection between the chamber 42 and the compartment 52. Thereafter, a cleaning fluid may flow from the compartment 42 through the compartment 52, the transverse bore 55 and the leak detection channel 54. Thus, these spaces are cleansed.

Upon removal of the pressure, the upper valve body portion 48 returns to that of FIG. 1 due to the influence of the spring 74.

By supplying a pressure medium, for example compressed air through the port 10 82, the auxiliary piston 64 is moved downward. By the contact of the auxiliary piston 64 with the shoulder 66 on the rod 65 of the lower valve body 49, the lower valve body portion 49 is also moved downwards. The upper valve body portion 48 is simultaneously guided by the abovementioned abutment stop means 69. Thus, the valve body 47 is moved downward as a whole. The seal ring 50 remains in contact with the valve seat 46 so that the chamber 42 remains blocked. However, seal ring 51 is released from valve seat 46 to establish a connection between chamber 43 and compartment 52. Again, the cleaning fluid may flow from chamber 43 through chamber 53, transverse bore 55, and leak detection channel 54 and out to purify these compartments. By relieving the pressure, the valve body 47 as a whole is returned by the return spring 59 to the one shown in FIG. 1.

25 In the closing valve 40, parts of the closing part are again connected to the housing 41 by means of clamping rings. By loosening the clamping rings, the closing valve 40 can be simply removed while the housing 41 remains in the pipe or duct system. In this way, replacement of sealing rings 30 or further cleaning operations can be made very quickly.

In FIG. 5 shows a closing valve 85 which is substantially similar to that of FIG. 1-4. Therefore, only the differences between valve 85 and valve 40 will be described.

8

DK 165519B

The movable part is as a whole mounted in the upper part of the closing valve. The return spring, which is composed of a spring 86 and a spring 87, which is inside the spring 86, is contained in a cylinder 90. A lower valve part 94 5 is connected to a valve shaft 97 by means of a pin 96. At that end of the valve shaft 97 extending above the cylinder 90 there is mounted a bushing 98 which is integral with the shaft by means of a nut 99 and a locking pin 100. At its lower end, the bushing 98 has a 10 flange against which springs 86 and 87 abut. The springs 86 and 87 are contained in a spring sleeve 88 resting against an upper flange of a collar 101 in the cylinder 90. The spring 95, which serves to force the valve members 94 and 93 to the relatively open position, is positioned close to the valve shaft 15 97. bottom end. The spring 95 lies with its upper end against a collar in the upper valve member 93 and with its lower end towards the upper side of the lower valve member 94.

\

To open the valve, a pressure medium is supplied through the port 91 to the cylinder 90. This pressure medium flows 20 through the opening 92 in the upper flange 88 of the spring bush to the space above the main piston 89. Firstly, the spring 95 is compressed, whereby the two valve parts 93 and 94 enter contact with each other. At the continued piston stroke of the main piston, the upper valve portion 93 is guided by the lower valve portion 94 against the biasing force of springs 86 and 87.

Establishment of the two rinsing positions corresponding to those in FIG. 3 and 4 for the valve 40 are similarly produced by applying pressure under the main piston 90, respectively, or acting on the auxiliary piston.

By simply loosening a clamping ring 102, the entire valve body with the movable portion can be removed by the valve body 103, as shown in FIG. 6. The movable portion contained in cylinder 90 can be released from the valve body by removing the locking pin 100 and by tightening the nut 99

Claims (6)

9 DK 165519B off. Thereafter, the valve body member 94 can be quickly removed from the valve member 93. The shaft 97 can be simply released from the lower valve body member 94 by removing it in FIG. 5, the movable part can be further dismantled by pressing a cover 105 downwards, after which a spring ring 104 can be removed. This cover, the auxiliary piston, the bushing 98, the springs and the spring bushing are thereby released. Therefore, the closing valve 85 can be manually separated at a moment 10 and with a few operations. Replacement of sealing rings and cleaning of the unit therefore becomes possible in a simple and quick way. A shut-off valve (40, 85) with a valve housing (41) having two chambers (42, 43) axially interconnected via a passage defined by a valve seat (46) and having valve ports for supplying and discharging a fluid; a valve body (47, 93, 94) disposed axially movable within the housing and having sealing members (50, 51) cooperating with the valve seat (46) to close the associated passage, the valve body (47) having a top portion (48) having a sealing member (50) and a lower member (49) having a sealing member (51), said portions (48, 49) being movable relative to each other in such a manner that there is a position of close 25 contact (Fig. 2) and a position in which a leak detection or flushing chamber (52) is formed between the valve body parts (48, 49) (Fig. 1), whereby one of the valve body parts (48 or 49) has formed a leak detection channel (54) extending from the leak detection chamber (52) to the outside of the valve housing (41); an operating device (62, 63, 80, 59) for bringing the valve into the open and closed positions and engaging with one end of the valve body (47), which body (47) is guided sealed on opposite sides of the valve housing (41) through DK 165519 B 10 passages in the valve body which have the same dimensions as the valve seat (46), the valve seat comprising a cylindrical surface (46) with the same dimensions as the passages, and the seal comprising at least one sealing ring (50, 51) its radially outer perimeter cooperating with the cylindrical valve seat (46) and abutment means for defining the open and closed position of the valve, characterized in that the sealing ring (50) is positioned on the valve body (47, 93, 94) on such in that the sealing ring (50, 51) during the closing and opening movements of the valve body in cooperation with the cylindrical surface performs the actual closing and opening of the passage (68), so that the valve body (47) is substantially ba launched 15 with respect to the forces resulting from the fluid pressure affecting the valve body in order to reduce the force required to operate the valve, a shutter member (53) being disposed between the axial surfaces of the valve body members (48, 49) to seal the leak detection chamber (52) with respect to the interior of the valve body when the valve is in its open position and the valve body portions (48, 49. are in their close contact position (FIG. 2); and wherein the movable portion is capable of establishing a first flush position (Fig. 3) in which a flush path 25 is formed from the first chamber (42) through the flush chamber (52) to the channel (54), and a second flush position ( Figure 4), in which a rinsing path is formed from the second chamber (43) through the rinsing chamber (52) to the channel (54), and abutment means for defining the two rinsing positions. 30 A shut-off valve according to claim 1, characterized in that the valve seat (46) has such an axial length that the two sealing parts (50, 51) in the relatively open position can be sealingly engaged with the valve seat (46). 11 DK 165519B A shut-off valve according to claim 1 or 2, characterized in that the movable part is connected to the valve housing by means of at least one attachment ring. Closure valve according to claim 2 or 3, characterized in that the movable part has a separate drive piston (47, 67, 64) for each of the valve body parts (48, 49) for moving the associated valve body part out of engagement with the valve seat (46). in the closed valve's closed position. A shut-off valve according to claim 4, characterized in that one of the drive pistons has a main piston (47, 67) for moving the valve body as a whole, that the stop means for defining the closed position of the valve body are compliant stop means (69), and that the main piston is capable of being displaced against the biasing force of the resilient impact members to move the associated valve body portion out of engagement with the valve seat (46). A shut-off valve according to any one of claims 2-5, characterized in that the compliant stop means (69) has a collar (71) on the upper part and a collar (70) on the lower part, which latter collar in the The relative open position (Fig. 1) extends for a total of substantially the same distance as the former collar and is positioned radially opposite to it, as well as spring-actuated pressure rings which engage on both sides of the two axial faces of the collar.